/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.db.mpp.plan.planner.plan.node.process.last;

import org.apache.iotdb.db.mpp.plan.planner.plan.node.PlanNode;
import org.apache.iotdb.db.mpp.plan.planner.plan.node.PlanNodeId;
import org.apache.iotdb.db.mpp.plan.planner.plan.node.PlanNodeType;
import org.apache.iotdb.db.mpp.plan.planner.plan.node.PlanVisitor;
import org.apache.iotdb.db.mpp.plan.planner.plan.node.process.MultiChildProcessNode;
import org.apache.iotdb.db.mpp.plan.planner.plan.parameter.OrderByParameter;

import java.io.DataOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.List;
import java.util.Objects;

import static org.apache.iotdb.db.mpp.plan.planner.plan.node.source.LastQueryScanNode.LAST_QUERY_HEADER_COLUMNS;

public class LastQueryMergeNode extends MultiChildProcessNode {

    // The result output order, which could sort by sensor and time.
    // The size of this list is 2 and the first SortItem in this list has higher priority.
    private final OrderByParameter mergeOrderParameter;

    public LastQueryMergeNode(PlanNodeId id, OrderByParameter mergeOrderParameter) {
        super(id);
        this.mergeOrderParameter = mergeOrderParameter;
    }

    public LastQueryMergeNode(
            PlanNodeId id, List<PlanNode> children, OrderByParameter mergeOrderParameter) {
        super(id, children);
        this.mergeOrderParameter = mergeOrderParameter;
    }

    @Override
    public List<PlanNode> getChildren() {
        return children;
    }

    @Override
    public void addChild(PlanNode child) {
        children.add(child);
    }

    @Override
    public PlanNode clone() {
        return new LastQueryMergeNode(getPlanNodeId(), mergeOrderParameter);
    }

    @Override
    public int allowedChildCount() {
        return CHILD_COUNT_NO_LIMIT;
    }

    @Override
    public List<String> getOutputColumnNames() {
        return LAST_QUERY_HEADER_COLUMNS;
    }

    @Override
    public String toString() {
        return String.format(
                "LastQueryMergeNode-%s:[OrderByParameter: %s]", this.getPlanNodeId(), mergeOrderParameter);
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        if (!super.equals(o)) {
            return false;
        }
        LastQueryMergeNode that = (LastQueryMergeNode) o;
        return mergeOrderParameter.equals(that.mergeOrderParameter);
    }

    @Override
    public int hashCode() {
        return Objects.hash(super.hashCode(), mergeOrderParameter);
    }

    @Override
    public <R, C> R accept(PlanVisitor<R, C> visitor, C context) {
        return visitor.visitLastQueryMerge(this, context);
    }

    @Override
    protected void serializeAttributes(ByteBuffer byteBuffer) {
        PlanNodeType.LAST_QUERY_MERGE.serialize(byteBuffer);
        mergeOrderParameter.serializeAttributes(byteBuffer);
    }

    @Override
    protected void serializeAttributes(DataOutputStream stream) throws IOException {
        PlanNodeType.LAST_QUERY_MERGE.serialize(stream);
        mergeOrderParameter.serializeAttributes(stream);
    }

    public static LastQueryMergeNode deserialize(ByteBuffer byteBuffer) {
        OrderByParameter mergeOrderParameter = OrderByParameter.deserialize(byteBuffer);
        PlanNodeId planNodeId = PlanNodeId.deserialize(byteBuffer);
        return new LastQueryMergeNode(planNodeId, mergeOrderParameter);
    }

    public void setChildren(List<PlanNode> children) {
        this.children = children;
    }

    public OrderByParameter getMergeOrderParameter() {
        return mergeOrderParameter;
    }
}
